Percentage of Participants With a Decrease From Baseline in 28-day Seizure Frequency of =50%(Responder) in the Maintenance Period(LOCF) [ Time Frame: Baseline (Week -8 to Week 0), and Week 8 to Week 20 ] [ Designated as safety issue: No ]

A participant with a decrease from baseline in seizure frequency of =50 % was considered a responder. Participants' parent or guardian maintained a seizure diary recording the date, number, and type of seizures the subject had. The primary analysis assessed the percent of responders in the Maintenance Period (28- day seizure frequency in Week 8 to Week 20 compared to Week -8 to Week 0 at Last Observation Carried Forward (LOCF)). Seizure frequency of simple partial, complex partial, and partial seizures with secondary generalization were assessed.

Secondary Outcome Measures:

Median Percent Change From Baseline in the 28-day Seizure Frequency During the Maintenance Period (LOCF) [ Time Frame: Baseline (Week -8 to Week 0) and Week 8 to Week 20 ] [ Designated as safety issue: No ]

Percent of Participants With =25% and =100% Increase From Baseline in 28-day Seizure Frequency During the Maintenance Period (LOCF) [ Time Frame: Baseline (Week -8 to Week 0) and Week 8 to Week 20 ] [ Designated as safety issue: No ]

Participants had a starting dose of 1 mg/kg/day of placebo matching Zonisamide. Dose was titrated upwards with weekly dose increases until a dose of 8 mg/kg/day was reached at the end of the Titration Period (Week 8). Dose during the Maintenance Period remained unchanged from Week 8.

Drug: Placebo

Experimental: Zonisamide

Participants had a starting dose of 1 mg/kg/day of Zonisamide. Dose was titrated upwards with weekly dose increases until a dose of 8 mg/kg/day was reached at the end of the Titration Period (Week 8). Dose during the Maintenance Period remained unchanged from Week 8.

Drug: Zonisamide

8mg/kg per day for approximately 24 weeks.

Other Name: Zonegran

Detailed Description:

This will be a double-blind, randomised, study comparing zonisamide with placebo: each arm will consist of 102 subjects. Zonisamide/placebo dosing will commence with a dose of 1 mg/kg. Further dose increases will occur at weekly intervals until a dose of 8 mg/kg is reached at the end of Week 8. In the event of dose limiting adverse events (AEs), during the eight week Titration Period, one down titration to a lower dose is permitted, this can happen at any point in the Titration Period. Subjects who require further down titration steps will be withdrawn from the study. During the Maintenance Period the dose of study medication must remain unchanged.

Changes in concomitant AEDs are not permitted during the Screening, Titration or Maintenance Periods.

This trial consists of the following periods:

Screening Period (duration four weeks): once the Screening Visit has been performed, a seizure diary will be maintained to document the baseline seizure frequency in the eight weeks between the Screening Visit and the Randomisation Visit.

Titration Period (duration four weeks): during this period, zonisamide/placebo dosing will commence with a dose of 1 mg/kg. Further dose increases will occur at one week intervals until a dose of 8 mg/kg is reached at Visit 6 (Week 8). In the event of dose limiting AEs during the Titration Period, one down titration step to the previous dose will be permitted.

Maintenance Period (duration 12 weeks): during this period, randomised subjects will be treated with the dose of zonisamide/placebo which they were receiving at Visit 6 (Week 8). No changes to the dose are allowed during this phase.

Following the Maintenance Period subjects will have the opportunity to enter an open label extension study. This open label extension study will be the subject of a separate protocol and will not be discussed further at this time.

Eligibility

Ages Eligible for Study:

6 Years to 17 Years

Genders Eligible for Study:

Both

Accepts Healthy Volunteers:

No

Criteria

Inclusion Criteria:

Subject is male or female aged 6-17 years inclusive.

Parent/guardian is willing to sign an approved informed consent form, and accompany the subject on all study visits.

Subject is willing to give informed (written or verbal) assent and if appropriate written informed consent.

Subject has a clinical diagnosis of epilepsy with partial-onset seizures with or without secondary generalized seizures according to the International League Against Epilepsy's Classification of Epileptic Seizures (1981).

Diagnosis has been established by clinical history, electroencephalogram (EEG) and computed tomography/ magnetic resonance imaging (CT/MRI) of the brain consistent with localization related epilepsy.

Subject has > four (simple or complex) partial seizures (with or without secondary generalization) per month over the eight week Screening Period with at least one seizure in each four week period and with no 21 day period being seizure free.

Subject is taking a stable regimen of one or two other AEDs for at least one month prior to Visit 1 (start of the Screening Period).

NOTE: If using a vagal nerve stimulator (VNS), it must have been implanted for at least five months and stimulator parameters must remain unchanged for at least one month prior to Visit 1 (start of the Screening Period), and throughout the entire study period. VNS will be considered as one AED for the purposes of this study.

Subject is in general good health as determined by medical history, physical exam and screening laboratory results.

Parent/guardian is willing and able to complete a seizure diary for the duration of the study.

Exclusion Criteria:

Subject of body weight < 20 kg at the Screening Visit.

Subject is unable to swallow capsules.

Subject has progressive neurological disease (determined by diagnosis or a pre-existing brain image such as a CT scan or MRI).

Subject has a history of idiopathic generalized epilepsy as defined by the International League Against Epilepsy (ILAE).

Subject has a history of status epilepticus within a year of the Screening Visit whilst taking AEDs.

Subject has seizures that only occur in clustered patterns, or has seizures that are too close together to count accurately.

Subject has a history of renal calculi or renal insufficiency (creatinine levels >194 µmol/l (1.5 mg1/dl).

Subject had a predisposing condition that might interfere with absorption, distribution, or excretion of zonisamide.

Subject has a history of psychiatric illness.

Subject has a history of suicide attempt.

Female subject who is pregnant or lactating.

Subject has a history of demonstrated non-compliance with treatment or, the subject, parent or legal guardian can be reasonably expected not to be compliant with study procedures or to complete the study.

Female subject of 10 years of age or greater or of child bearing potential (i.e., started menses) and is not taking or prepared to take a medically acceptable form of contraception (i.e., oral contraceptive pill, surgical sterilization, an implant or an injected form of contraception, or intrauterine device), or who is not prepared to abstain from sexual activity for the duration of the study and one month after last administration of study medication.

NOTE: Should a female subject become of childbearing potential during the study, they must be reconsented in order to give consent to undergo pregnancy testing and either confirm abstinence or receive medically appropriate form of contraception.

Subjects who do not have a complete seizure diary during the Screening Period.

Subjects with active and/or insufficiently treated neurocysticerosis or intercraniel tubiculosis. Note: subjects who have completed a curative antihelminthic or antituberculous treatment course more than 3 months before screening and who are free of signs and symptoms of active infection (including on a post treatment CT/MRI scan), may be enrolled in the study.

Subjects taking antipsychotics, monoamine oxidase inhibitors (MAOIs), tricyclic antidepressants (TCAs) and benzodiazepines with barbiturates and amphetamines for disease other than epilepsy within 3 months of screening.

Contacts and Locations

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Please refer to this study by its ClinicalTrials.gov identifier: NCT00566254